Commercial airlines are continuously demanding airplanes that maximize revenue while reducing operational costs. It is likewise demanded that new airplanes comply with the current and future environmental standards.
This demand requires airplanes having low fuel consumption and being configured so as to facilitate efficient passenger embarking/disembarking and cargo loading/unloading operations in order to maximize the number of flight missions carried out in a given time. It is also required that aircraft design allows optimum use of internal volumes for a wide range of different airlines that have different requirements in terms of passengers, baggage and freight capacity.
Double-deck airplanes are one of the available options to meet that demand because in classical commercial aircraft configurations with an upper deck dedicated almost exclusively to carrying passengers and a lower hold only dedicated to cargo transportation it is not possible, for example, to use the empty cargo space to carry more passengers on a flight with no or little cargo being transported.
US 2004/0075025 describes an aircraft comprising an upper deck, a multipurpose lower deck and a wing structure passing through the lower deck area which leads to having separated front and aft portions on the lower deck. Thus the flexibility of use and the volume of the lower deck are limited by the presence of the wing.
US 2013/0099053 describes a double-deck airplane with a mid-wing. The airplane is configured with an upper compartment for passengers and a lower compartment with a frontal portion for passengers, a rear portion for cargo and an intermediate portion for the wing box and other facilities. This configuration is determined by the use of high bypass ratio turbofan engines or open rotor engines mounted on the underside of the wing and has the drawback that the wing box occupies a useful space for passengers or cargo inside the fuselage.
The technology herein is directed to solving all the problems mentioned above.